PARIS — Starting in early 2009, almost any word will be able to replace “.com” or “.net” in a Web page address, thanks to a decision on Thursday by the international group controlling Internet addresses.

Get ready for a nearly infinite variety of new Web addresses ending in “.perfume,” “.sports,” “.nyc” and “.prettymuchanythingyouwant.”

Heralding the most dramatic expansion of virtual real estate in 40 years, the Internet Corporation for Assigned Names and Numbers, or ICANN, said any company, organization or country will soon be able to apply for a new Web address extension, called a top-level domain.

The news is likely to spark a scramble for desirable addresses, and could force businesses to register thousands of domains to protect their brands. And it could make some Web pages easier — and some harder — to find.

“It is an amazing development,” says Tom Lowenhaupt, who heads Connecting.nyc, a New York City community group pushing for a “.nyc” domain.

It could create a host of new ways to exploit the Web addressing system and trigger a wave of legal skirmishes over applications to register trademarks — “.coke,” for example.

ICANN officials said any applications for the new domains would have to go through an independent review process. Third parties will be able to challenge applications on the grounds that a particular suffix could threaten “morality and public order.” And companies will have the first priority when it comes to claiming their brand names.

If multiple parties want a name — as is already the case with “.sports” — conflicts will be settled through auctions.

Currently, the domain-name system consists of more than 20 suffixes, which follow the last dot in a Web address. Domains have so far been generally restricted to labels for countries — “.ca” for Canada, for example — and descriptions for broad categories like “.com” for commerce and “.org” for institutional organizations.

Address extensions that ICANN added more recently, like “.biz” in 2001 and “.mobi” in 2005, have been largely ignored and in some cases have been adopted mostly by spammers and other maldoers.

“We’re expecting a broad range of applicants. Indigenous communities might come forward to protect aspects of their language and culture,” said Peter Dengate Thrush, ICANN’s chairman. “We may see a ‘.smith’ so that all the Smiths in the world will have a place.

“It’s very exciting to see what people will do with those names,” he said.

Ron Jackson, editor of Domain Journal, an industry newsletter, said he thought the new addresses would addle average Internet users. “If you have hundreds or thousands of new suffixes, they are not that easy to remember. I just see it as confusing,” he said.

Lauren Weinstein, a longtime Internet activist and co-founder of People for Internet Responsibility, an education and policy firm in Los Angeles, said he worried the new system would create huge opportunities for shady domain-name registrars, who buy and sell domain names for profit, and for others who try to exploit the address system.

“The potential for mass confusion and fraud and phishing from these new domains seems to be what the primary impact will be for consumers,” Weinstein said. “I fail to see the positive for consumers in this. It’s all downside.”

One question is how much the new top-level domains will cost. ICANN officials estimated that prices would start in the low six figures, so the organization can recoup its expenses for developing the new service. Popular domains could be auctioned, Twomey says.

The ICANN board also passed another less-controversial proposal that would allow these domains to be registered in scripts other than Roman characters, like Chinese, Arabic and Cyrillic.

Big winners are companies that sell domain names, such as Network Solutions and GoDaddy.com, says Gordon Cook, author of the Cook Report on Internet trade newsletter.

They could reap huge profits from new applications. Cook argues that ICANN is too closely aligned with their interests, but Twomey says his group is just fulfilling a pledge to give Web-site owners more options.

Avi Silberschatz, chair of the computer-science department at Yale University, says few people type in domain names anymore. Instead, they use search engines, he says.

” ‘Yale.edu,’ ‘whitehouse.gov,’ who remembers it?” he says. “You just go to Google.”

Compiled from The New York Times, Gannett News Service, The Associated Press and Los Angeles Times